Targeted and untargeted lipidomics with integration of liver dynamics and microbiome after dietary reversal of obesogenic diet targeting inflammation-resolution signaling in aging mice.

Obesity, a global epidemic linked to around 4 million deaths yearly, arises from lifestyle imbalances impacting inflammation-related conditions like non-alcoholic fatty liver disease and gut dysbiosis. But the long-term effects of inflammation caused by lifestyle-related dietary changes remain unexplained. In this study, we used young male C57Bl/6 mice which were fed either an obesogenic diet (OBD) or a control diet (CON) for six months. Later, a group of mice from the OBD group were intervened to the CON diet (OBD-R) for four months, while another OBD group remained on the OBD diet. The OBD induced distinct changes in gut microbial, notably elevating Firmicutes and Actinobacteria, while reducing Bacteroidetes and Tenericutes. OBD-R restored microbial abundance like CON. Analyzing liver, plasma, and fecal samples revealed OBD-induced alterations in various structural and bioactive lipids, which were normalized to CON in the OBD-R, showcasing lipid metabolism flexibility and adaptability to dietary shifts. OBD increased omega 6 fatty acid, Arachidonic Acid (AA) and decreased omega 3-derived lipid mediators in the OBD mimicking non-alcoholic fatty liver disease thus impacting inflammation-resolution pathways. OBD also induced hepatic inflammation via increasing alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and proinflammatory markers CCR2, TNF-α, and IL-1ß in liver. Transitioning from OBD to CON mitigated inflammatory gene expression and restored lipid and cholesterol networks. This study underscores the intricate interplay between lifestyle-driven dietary changes, gut microbiota, lipid metabolism, and liver health. Notably, it suggests that shift from an OBD (omega-6 enriched) to CON partially alleviates signs of chronic inflammation during aging. Understanding these microbial, lipidomic, and hepatic inflammatory dynamics reveals potential therapeutic avenues for metabolic disorders induced by diet, emphasizing the pivotal role of diet in sustaining metabolic health.

Contributing factors for reduction in maternal mortality ratio in India.

Maternal mortality ratio (MMR) estimates have been studied over time for understanding its variation across the country. However, it is never sufficient without accounting for presence of variability across in terms of space, time, maternal and system level factors. The study endeavours to estimate and quantify the effect of exposures encompassing all maternal health indicators and system level indicators along with space-time effects influencing MMR in India. Using the most recent level of possible -factors of MMR, maternal health indicators from the National Family Health Survey (NFHS: 2019-21) and system level indicators from government reports a heatmap compared the relative performance of all 19 SRS states. Facet plots with a regression line was utilised for studying patterns of MMR for different states in one frame. Using Bayesian Spatio-temporal random effects, evidence for different MMR patterns and quantification of spatial risks among individual states was produced using estimates of MMR from SRS reports (2014-2020). India has witnessed a decline in MMR, and for the majority of the states, this drop is linear. Few states exhibit cyclical trend such as increasing trends for Haryana and West Bengal which was evident from the two analytical models i.e., facet plots and Bayesian spatio- temporal model. Period of major transition in MMR levels which was common to all states is identified as 2009-2013. Bihar and Assam have estimated posterior probabilities for spatial risk that are relatively greater than other SRS states and are classified as hot spots. More than the individual level factors, health system factors account for a greater reduction in MMR. For more robust findings district level reliable estimates are required. As evident from our study the two most strong health system influencers for reducing MMR in India are Institutional delivery and Skilled birth attendance.

Hidden hunger in patients with type 2 diabetes (T2D) and its effect on glycaemic control: a protocol for systematic review and meta-analysis.

INTRODUCTION: Hidden hunger or micronutrient deficiencies are quite common in many parts of the world, particularly in the countries of sub-Saharan Africa and South Asia. Micronutrient deficiencies may impact insulin signalling pathways and glucose metabolism, potentially accelerating the onset and development of type 2 diabetes (T2D). This review aims to estimate the prevalence of multiple micronutrient deficiencies among patients with T2D and assess the effect of their deficiency on glycaemic control. METHODOLOGY: The review follows the Cochrane Handbook and PRISMA 2020 guidelines. It includes all eligible studies reporting the prevalence of micronutrient deficiencies and their effect on glycaemic control in T2D patients. We would undertake a comprehensive literature search across databases: PubMed, Scopus, EMBASE, LILACS, ProQuest, Google Scholar and grey literature, and identify the studies meeting the inclusion criteria. We would perform data extraction using a prepiloted data extraction sheet and record relevant study characteristics and outcomes. ANALYSIS: Data will be analysed using JBI Sumari software and R software. Pooled prevalence/incidence of micronutrient deficiency will be estimated, and variance will be stabilised using logit transformation and a double-arcsine transformation of the data. The OR and risk ratio of glycaemic control among T2D cases with and without micronutrient deficiency will be estimated using the 'rma' function under the 'meta' and 'metafor' packages.The study findings will have implications for diabetes management strategies and may inform interventions targeting improved glycaemic control through addressing micronutrient deficiencies. ETHICS AND DISSEMINATION: This systematic review will be based on the scientific information available in the public domain; therefore, ethics approval is not required. We will share the study findings at national and international conferences and submit them for publication in relevant scientific journals. PROSPERO REGISTRATION NUMBER: CRD42023439780.

Abnormalities in microbiota/butyrate/FFAR3 signaling in aging gut impair brain function.

Aging-related abnormalities in gut microbiota are associated with cognitive decline, depression, and anxiety, but underlying mechanisms remain unstudied. Here, our study demonstrated that transplanting old gut microbiota to young mice induced inflammation in the gut and brain coupled with cognitive decline, depression, and anxiety. We observed diminished mucin formation and increased gut permeability ("leaky gut") with a reduction in beneficial metabolites like butyrate because of decline in butyrate-producing bacteria in the aged gut microbiota. This led to suppressed expression of butyrate receptors, free fatty acid receptors 2 and 3 (FFAR2/3). Administering butyrate alleviated inflammation, restored mucin expression and gut barriers, and corrected brain dysfunction. Furthermore, young mice with intestine-specific loss of FFAR2/3 exhibited gut and brain abnormalities akin to those in older mice. Our results demonstrate that reduced butyrate-producing bacteria in aged gut microbiota result in low butyrate levels and reduced FFAR2/3 signaling, leading to suppressed mucin formation that increases gut permeability, inflammation, and brain abnormalities. These findings underscore the significance of butyrate-FFAR2/3 agonism as a potential strategy to mitigate aged gut microbiota-induced detrimental effects on gut and brain health in older adults.

Examining birth preparedness and complication readiness: a systematic review and meta-analysis of pregnant and recently delivered women in India.

BACKGROUND: Birth preparedness and complication readiness (BPCR) is an essential component of safe motherhood programs. This study aims to systematically identify and synthesize available evidence on birth preparedness and complication readiness among pregnant and recently delivered women in India. METHODS: The study followed PRISMA guidelines and used databases such as PubMed, Cochrane Library, and ProQuest. Joanna Briggs Institute [JBI] Tool was used for critical appraisal of studies. The meta-analysis was conducted using Comprehensive Meta-Analysis [CMA] tool and R studio software. Statistical heterogeneity was evaluated using visual inspection of the forest plot, Cochran's Q test, and the I2 statistic results. Funnel plot and Egger's tests were applied to explore the possibility of the publication bias in the studies [PROSPERO: CRD42023396109]. RESULT: Thirty-five cross-sectional studies reported knowledge on one or more components of birth preparedness [BP], whilst knowledge on complication readiness [CR] or danger signs was reported in 34 included studies. Utilizing the random effect model, the pooled result showed that only about half of the women [49%; 95% CI: 44%, 53%] were aware on BPCR components. This result ranged between 15% [95% CI: 12%, 19%] to 79% [95% CI: 72%, 84%] in Maharashtra and Karnataka respectively [I2 = 94%, p = < 0.01]. High heterogeneity [> 90%] is observed across all components [p < 0.01]. The result of subgroup analysis indicated no significant difference in the proportion on BPCR among pregnant women [50%; 95% CI: 45%, 55%] and recently delivered women [54%; 95% CI: 46%, 62%]. However, the southern region of India indicates relatively better [56%; 95% CI: 45%, 67%] prevalence. CONCLUSION: Our study highlights the low prevalence of BPCR in India and the factors associated with it. Scaling up cost-effective interventions like BPCR that have a positive overall effect is necessary. Authors strongly suggests that birth preparedness and complication readiness should be given utmost importance to reduce maternal morbidity and mortality to achieve the Sustainable Development Goals. Consideration should be given to fortifying existing resources, such as frontline workers and primary healthcare, as a strategic approach to augmenting the effectiveness of awareness initiatives.

Intestinal FFA2 promotes obesity by altering food intake in Western diet-fed mice.

Short-chain fatty acids (SCFAs) are key nutrients that play a diverse set of roles in physiological function, including regulating metabolic homeostasis. Generated through the fermentation of dietary fibers in the distal colon by the gut microbiome, SCFAs and their effects are partially mediated by their cognate receptors, including free fatty acid receptor 2 (FFA2). FFA2 is highly expressed in the intestinal epithelial cells, where its putative functions are controversial, with numerous in vivo studies relying on global knockout mouse models to characterize intestine-specific roles of the receptor. Here, we used the Villin-Cre mouse line to generate a novel, intestine-specific knockout mouse model for FFA2 (Vil-FFA2) to investigate receptor function within the intestine. Because dietary changes are known to affect the composition of the gut microbiome, and can thereby alter SCFA production, we performed an obesogenic challenge on male Vil-FFA2 mice and their littermate controls (FFA2-floxed, FFA2fl/fl) to identify physiological changes on a high-fat, high-sugar 'Western diet' (WD) compared to a low-fat control diet (CD). We found that the WD-fed Vil-FFA2 mice were transiently protected from the obesogenic effects of the WD and had lower fat mass and improved glucose homeostasis compared to the WD-fed FFA2fl/fl control group during the first half of the study. Additionally, major differences in respiratory exchange ratio and energy expenditure were observed in the WD-fed Vil-FFA2 mice, and food intake was found to be significantly reduced at multiple points in the study. Taken together, this study uncovers a novel role of intestinal FFA2 in mediating the development of obesity.

Assessment of needs and gaps in public health cadre in India - a situational analysis.

BACKGROUND: A structured and organized public health set up with systematically trained personnel to manage and deliver public health services from grassroot levels to higher administrative levels with separate public health directorate is the need of the hour. The objective of this study was to conduct a situational analysis of public health cadre in select states in India to gain an in-depth understanding of the progress and explore the gaps and challenges in its implementation. METHODS: Four states from the country were selected based on stages of implementation of the cadre. The WHO health systems framework was the basis of assessment. In-depth interviews of 78 stakeholders from public health system across various categories and levels were conducted. RESULTS: Every state has a dedicated cadre for public health in the form of a separate hierarchical structure and Directorate. There are deficits in human resources skilled enough to manage and implement public health across all levels. Its penetration below districts level is limited. There are limited opportunities available for contractual staffs in terms of remuneration and job progression. The respondents strongly emphasized on having personnel with training in public health, especially at leadership positions. Funding was not reported to be a problem although some challenges in the timeliness of release of funds were reported. Under the existing Health Management Information System, duplication of data exists and there is underutilization of data for policy making. CONCLUSION: A dedicated public health cadre is under evolution in India. The main challenge is inadequate workforce skilled in public health management. States are committed to finding solutions to overcome these barriers.

The Triple Alliance: Microbiome, Mitochondria, and Metabolites in the Context of Age-Related Cognitive Decline and Alzheimer's Disease.

Alzheimer's disease (AD) is a progressive, age-related neurodegenerative disorder that affects a large proportion of the older population. It currently lacks effective treatments, placing a heavy burden on patients, families, health care systems, and society. This is mainly due to our limited comprehension of the pathophysiology of AD progression, as well as the lack of effective drug targets and intervention timing to address the underlying pathology. AD is a multifactorial condition, and emerging evidence suggests that abnormalities in the gut microbiota play a significant role as environmental and multifaceted contributors to AD, although the exact mechanisms are yet to be fully explored. Changes in the composition of microbiota influence host neuronal health through their metabolites. These metabolites regulate intestinal epithelia, blood-brain barrier permeability, and neuroinflammation by affecting mitochondrial function. The decline in the proportion of beneficial microbes and their essential metabolites during aging and AD is directly linked to poor mitochondrial function, although the specific mechanisms remain unclear. In this review, we discuss recent developments in understanding the impact of the microbiome and its metabolites on various cell types, their influence on the integrity of the gut and blood-brain barriers, systemic and brain inflammation, and cell-specific effects in AD pathology. This information is expected to pave the way for a new understanding of the interactions between microbiota and mitochondria in AD, providing a foundation for the development of novel treatments for AD.

Unique trans-kingdom microbiome structural and functional signatures predict cognitive decline in older adults.

The prevalence of age-related cognitive disorders/dementia is increasing, and effective prevention and treatment interventions are lacking due to an incomplete understanding of aging neuropathophysiology. Emerging evidence suggests that abnormalities in gut microbiome are linked with age-related cognitive decline and getting acceptance as one of the pillars of the Geroscience hypothesis. However, the potential clinical importance of gut microbiome abnormalities in predicting the risk of cognitive decline in older adults is unclear. Till now the majority of clinical studies were done using 16S rRNA sequencing which only accounts for analyzing bacterial abundance, while lacking an understanding of other crucial microbial kingdoms, such as viruses, fungi, archaea, and the functional profiling of the microbiome community. Utilizing data and samples of older adults with mild cognitive impairment (MCI; n = 23) and cognitively healthy controls (n = 25). Our whole-genome metagenomic sequencing revealed that the gut of older adults with MCI harbors a less diverse microbiome with a specific increase in total viruses and a decrease in bacterial abundance compared with controls. The virome, bacteriome, and microbial metabolic signatures were significantly distinct in subjects with MCI versus controls. Selected bacteriome signatures show high predictive potential of cognitive dysfunction than virome signatures while combining virome and metabolic signatures with bacteriome boosts the prediction power. Altogether, the results from our pilot study indicate that trans-kingdom microbiome signatures are significantly distinct in MCI gut compared with controls and may have utility for predicting the risk of developing cognitive decline and dementia- debilitating public health problems in older adults.

The effects of prebiotics on gastrointestinal side effects of metformin in youth: A pilot randomized control trial in youth-onset type 2 diabetes.

Disclosure summary: Dr. Yadav is Chief Scientific Officer and Co-Founder of Postbiotics Inc and has no conflict of interest with this work. All other authors have no conflicts of interest to disclose. Background: Metformin is the only approved first-line oral glucose lowering agent for youth with type 2 diabetes mellitus (Y-T2DM) but often causes gastrointestinal (GI) side effects, which may contribute to reduced treatment adherence and efficacy. Prebiotic intake may reduce metformin's side effects by shifting microbiota composition and activity. Objective: The aims of this study were to determine the feasibility and tolerability of a prebiotic supplement to improve metformin-induced GI symptoms and explore the changes in glycemia and shifts in the microbiota diversity. Methods: In a two-phase pilot clinical trial, we compared, stool frequency and stool form every 1-2 days, and composite lower GI symptoms (weekly) at initiation of daily metformin combined with either a daily prebiotic or a placebo shake in a 1-week randomized double-blind crossover design (Phase 1), followed by a 1-month open-labeled extension (Phase 2). Plasma glycemic markers and stool samples were collected before and after each phase. Results: Six Y-T2DM (17.2 ± 1.7y (mean ± SD), 67% male, BMI (42 ± 9 kg/m2), HbA1c (6.4 ± 0.6%)) completed the intervention. Stool frequency, stool composition, and GI symptom scores did not differ by group or study phase. There were no serious or severe adverse events reported, and no differences in metabolic or glycemic markers. After one week Phase 1metformin/placebo Proteobacteria, Enterobacteriaceae, and Enterobacteriales were identified as candidate biomarkers of metformin effects. Principle coordinate analyses of beta diversity suggested that the metformin/prebiotic intervention was associated with distinct shifts in the microbiome signatures at one week and one month. Conclusion: Administration of a prebiotic fiber supplement during short-term metformin therapy was well tolerated in Y-T2DM and associated with modest shifts in microbial composition. This study provides a proof-of-concept for feasibility exploring prebiotic-metformin-microbiome interactions as a basis for adjunctive metformin therapy. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT04209075.

A mechanism by which gut microbiota elevates permeability and inflammation in obese/diabetic mice and human gut.

OBJECTIVE: Ample evidence exists for the role of abnormal gut microbiota composition and increased gut permeability ('leaky gut') in chronic inflammation that commonly co-occurs in the gut in both obesity and diabetes, yet the detailed mechanisms involved in this process have remained elusive. DESIGN: In this study, we substantiate the causal role of the gut microbiota by use of faecal conditioned media along with faecal microbiota transplantation. Using untargeted and comprehensive approaches, we discovered the mechanism by which the obese microbiota instigates gut permeability, inflammation and abnormalities in glucose metabolism. RESULTS: We demonstrated that the reduced capacity of the microbiota from both obese mice and humans to metabolise ethanolamine results in ethanolamine accumulation in the gut, accounting for induction of intestinal permeability. Elevated ethanolamine increased the expression of microRNA-miR-101a-3p by enhancing ARID3a binding on the miR promoter. Increased miR-101a-3p decreased the stability of zona occludens-1 (Zo1) mRNA, which in turn, weakened intestinal barriers and induced gut permeability, inflammation and abnormalities in glucose metabolism. Importantly, restoring ethanolamine-metabolising activity in gut microbiota using a novel probiotic therapy reduced elevated gut permeability, inflammation and abnormalities in glucose metabolism by correcting the ARID3a/miR-101a/Zo1 axis. CONCLUSION: Overall, we discovered that the reduced capacity of obese microbiota to metabolise ethanolamine instigates gut permeability, inflammation and glucose metabolic dysfunctions, and restoring ethanolamine-metabolising capacity by a novel probiotic therapy reverses these abnormalities. TRIAL REGISTRATION NUMBER: NCT02869659 and NCT03269032.

Intestinal FFA3 mediates obesogenic effects in mice on a Western diet.

Free fatty acid receptor 3 (FFA3) is a recently-deorphanized G-protein-coupled receptor. Its ligands are short-chain fatty acids (SCFAs), which are key nutrients derived from the gut microbiome fermentation process that play diverse roles in the regulation of metabolic homeostasis and glycemic control. FFA3 is highly expressed within the intestine, where its role and its effects on physiology and metabolism are unclear. Previous in vivo studies involving this receptor have relied on global knockout mouse models, making it difficult to isolate intestine-specific roles of FFA3. To overcome this challenge, we generated an intestine-specific knockout mouse model for FFA3, Villin-Cre-FFA3 (Vil-FFA3). Model validation and general metabolic assessment of male mice fed a standard chow diet revealed no major congenital defects. Because dietary changes are known to alter gut microbial composition, and thereby SCFA production, an obesogenic challenge was performed on male Vil-FFA3 mice and their littermate controls to probe for a phenotype on a high-fat, high-sugar "Western diet" (WD) compared with a low-fat control diet (CD). Vil-FFA3 mice versus FFA3fl/fl controls on WD, but not CD, were protected from the development of diet-induced obesity and exhibited significantly less fat mass as well as smaller adipose depositions and adipocytes. Although overall glycemic control was unchanged in the WD-fed Vil-FFA3 group, fasted glucose levels trended lower. Intestinal inflammation was significantly reduced in the WD-fed Vil-FFA3 mice, supporting protection from obesogenic effects. Furthermore, we observed lower levels of gastric inhibitory protein (GIP) in the WD-fed Vil-FFA3 mice, which may contribute to phenotypic changes. Our findings suggest a novel role of intestinal FFA3 in promoting the metabolic consequences of a WD, including the development of obesity and inflammation. Moreover, these data support an intestine-specific role of FFA3 in whole body metabolic homeostasis and in the development of adiposity.NEW & NOTEWORTHY Here, we generated a novel intestine-specific knockout mouse model for FFA3 (Vil-FFA3) and performed a comprehensive metabolic characterization of mice in response to an obesogenic challenge. We found that Vil-FFA3 mice fed with a Western diet were largely protected from obesity, exhibiting significantly lower levels of fat mass, lower intestinal inflammation, and altered expression of intestinal incretin hormones. Results support an important role of intestinal FFA3 in contributing to metabolism and in the development of diet-induced obesity.

Activation of Microbiota Sensing - Free Fatty Acid Receptor 2 Signaling Ameliorates Amyloid-ß Induced Neurotoxicity by Modulating Proteolysis-Senescence Axis.

Multiple emerging evidence indicates that the gut microbiota contributes to the pathology of Alzheimer's disease (AD)-a debilitating public health problem in older adults. However, strategies to beneficially modulate gut microbiota and its sensing signaling pathways remain largely unknown. Here, we screened, validated, and established the agonists of free fatty acid receptor 2 (FFAR2) signaling, which senses beneficial signals from short chain fatty acids (SCFAs) produced by microbiota. The abundance of SCFAs, is often low in the gut of older adults with AD. We demonstrated that inhibition of FFAR2 signaling increases amyloid-beta (Aß) stimulated neuronal toxicity. Thus, we screened FFAR2 agonists using an in-silico library of more than 144,000 natural compounds and selected 15 of them based on binding with FFAR2-agonist active sites. Fenchol (a natural compound commonly present in basil) was recognized as a potential FFAR2 stimulator in neuronal cells and demonstrated protective effects against Aß-stimulated neurodegeneration in an FFAR2-dependent manner. In addition, Fenchol reduced AD-like phenotypes, such as Aß-accumulation, and impaired chemotaxis behavior in Caenorhabditis (C.) elegans and mice models, by increasing Aß-clearance via the promotion of proteolysis and reduced senescence in neuronal cells. These results suggest that the inhibition of FFAR2 signaling promotes Aß-induced neurodegeneration, while the activation of FFAR2 by Fenchol ameliorates these abnormalities by promoting proteolytic Aß-clearance and reducing cellular senescence. Thus, stimulation of FFAR2 signaling by Fenchol as a natural compound can be a therapeutic approach to ameliorate AD pathology.

Corneal transplantation during COVID-19 pandemic: need for special considerations-A live review.

Corneal blindness is the fourth leading cause of blindness worldwide, with 10 million people having bilateral corneal blindness, nearly 80% of all corneal blindness cases are avoidable and are reversible. Corneal transplantation (CT) is the most frequently performed type of transplant across the world. This review was conducted with the objective of identifying if it is safe to harvest the cornea from the patients died due to COVID-19 and preventing the chances of transmission from donor to the recipient or healthcare worker handling the harvested cornea. A total of 45 articles were found with the keywords and out of all, only 16 fulfilled the inclusion criteria. RT-PCR is the technique of choice for detection of virus in the corpse and the sample analyzed was a pharyngeal swab. Available literature states unavailability of sufficient evidence-based studies proving presence of virus in the cornea or tear of COVID affected patients There is no proven consensus on presence of Virus in cornea. It is important to follow preferred practice guidelines so as to restart eye banking and do at least the emergency surgeries without having risk of disease transmission and keeping ourselves safe.

Current perspectives on the occurrence of Q fever: highlighting the need for systematic surveillance for a neglected zoonotic disease in Indian subcontinent.

Coxiellosis or Q fever is an important global occupational zoonotic disease caused by one of the most contagious bacterial pathogens - Coxiella burnetii, which ranks one among the 13 global priority zoonoses. The detection of C. burnetii infection is exhibiting an increasing trend in high-risk personnel around the globe. It has increasingly been detected from foods of animal origin (including bulk milk, eggs, and meat) as well as tick vectors in many parts of the world. Coxiellosis is reported to be an important public health threat causing spontaneous abortions in humans and potential reproductive failure, which would result in production losses among livestock. Further, comprehensive coverage of the reports and trends of Q fever in developing countries, where this infection is supposed to be widely prevalent appears scarce. Also, the pathogen remains grossly neglected and underreported. Moreover, policymakers and funding agencies do not view it as a priority problem, especially in the Indian subcontinent, including Sri Lanka, Bhutan, Pakistan, Nepal, Bangladesh and Maldives. Here, we review the occurrence and epidemiology of the disease in a global context with special emphasis on its status in the Indian subcontinent.

New Horizons in Microbiota and Metabolic Health Research.

Decade-old studies have demonstrated that microbes living in our gut (microbiota) contribute to both maintaining normal metabolic function and to the pathology of metabolic diseases, such as obesity and diabetes. Emerging evidence suggests that gut microbiota influences the personalized effects of diets and drugs and impact the gut-brain axis and leaky gut inflammation to control metabolic function/diseases. Gut microbiota can be an ideal source of prognostic markers and therapies for metabolic diseases. Here we discuss the emerging concepts in the area of microbiota and metabolic interactions in personalized nutrition, drug response, and disease prognosis.

Gut mycobiome and its interaction with diet, gut bacteria and alzheimer's disease markers in subjects with mild cognitive impairment: A pilot study.

BACKGROUND: Recently, we reported that patients with mild cognitive impairment (MCI) harbor specific signature of bacteria in their gut and that a modified Mediterranean ketogenic diet (MMKD) improves Alzheimer's disease (AD) markers in cerebrospinal fluid (CSF) and the signatures of gut bacteria. However, other microbial population such as gut fungi (mycobiome) in relation to MCI/AD pathology, gut bacteria and diet remain unknown. METHODS: We measure gut mycobiome by sequencing of the fungal rRNA ITS1 gene in 17 older adults (11 MCI; 6 cognitively normal [CN]) in a single-center, randomized, double-blind, crossover pilot study, before and after 6 weeks intervention of MMKD and American Heart Association Diet (AHAD), and determine its correlation with AD markers in CSF and gut bacteria. FINDINGS: Compared to CN counterparts, patients with MCI have higher proportion of families Sclerotiniaceae, Phaffomyceteceae, Trichocomaceae, Cystofilobasidiaceae, Togniniaceae and genera Botrytis, Kazachstania, Phaeoacremonium and Cladosporium and lower abundance of Meyerozyma. Specific fungal taxa exhibit distinct correlation arrays with AD markers and gut bacteria in subjects with versus without MCI. MMKD induces broader effect on fungal diversity in subjects with MCI and increases Agaricus and Mrakia while decreasing Saccharomyces and Claviceps with differential response in subjects with or without MCI. INTERPRETATION: The study reveals MCI-specific mycobiome signatures and demonstrates that distinct diets modulate the mycobiome in association with AD markers and fungal-bacterial co-regulation networks in patients with MCI. The findings corroborate the notion of considering gut mycobiome as a unique factor that can affect cognitive health/AD by interacting with gut bacteria and diet and facilitate better understanding of the AD and related microbiome, using unique diet or microbiome modulators.

Free Fatty Acid Receptors 2 and 3 as Microbial Metabolite Sensors to Shape Host Health: Pharmacophysiological View.

The role of the gut microbiome in human health is becoming apparent. The major functional impact of the gut microbiome is transmitted through the microbial metabolites that are produced in the gut and interact with host cells either in the local gut environment or are absorbed into circulation to impact distant cells/organs. Short-chain fatty acids (SCFAs) are the major microbial metabolites that are produced in the gut through the fermentation of non-digestible fibers. SCFAs are known to function through various mechanisms, however, their signaling through free fatty acid receptors 2 and 3 (FFAR2/3; type of G-coupled protein receptors) is a new therapeutic approach. FFAR2/3 are widely expressed in diverse cell types in human and mice, and function as sensors of SCFAs to change several physiological and cellular functions. FFAR2/3 modulate neurological signaling, energy metabolism, intestinal cellular homeostasis, immune response, and hormone synthesis. FFAR2/3 function through Gi and/or Gq signaling, that is mediated through specific structural features of SCFAs-FFAR2/3 bindings and modulating specific signaling pathway. In this review, we discuss the wide-spread expression and structural homologies between human and mice FFAR2/3, and their role in different human health conditions. This information can unlock opportunities to weigh the potential of FFAR2/3 as a drug target to prevent human diseases.